LIPOPROTEIN (A) IS INCREASED IN ACUTE CORONARY SYNDROMES (UNSTABLE ANGINA-PECTORIS AND MYOCARDIAL-INFARCTION), BUT IT IS NOT PREDICTIVE OF THE SEVERITY OF CORONARY LESIONS

Lipoprotein (a) [Lp(a)] concentrations were determined in 365 patients undergoing coronary angiography for stable angina (n = 159), unstable angina (n = 99), recent myocardial infarction (n = 45), and nonischem ic heart disease (cardiomyopathy or valvular disease, n = 62, non-IHD) . Mean +/- SD and median Lp(a) concentrations in stable angina (29.9 /- 29.2; 22 mg/dl) did not differ from those in non-IHD (26.9 +/- 26.3 ; 17), but were significantly lower than in patients with unstable ang ina (52.7 +/- 36.6; 58) and myocardial infarction (44.8 +/- 36.4; 34) (p < 0.01). Coronary angiography revealed that 261 patients, including 4 patients in the non-IHD group, had significant (greater than or equ al to 50%) coronary lesions. Lp(a) was higher in patients with (41 +/- 35; 32) than in those without (28 +/- 27; 19) angiographic evidence o f significant coronary stenosis (p < 0.05) and showed a weak univariat e correlation with the angiographic index (Total Score) of the severit y of the disease (r = 0.106; p < 0.05), However, in the subgroup of 30 3 patients with stable/unstable angina or myocardial infarction, Lp(a) was predictive neither of angiographic presence nor of severity of co ronary disease. Patients were then ranked according to the Total Score values. Among patients with comparable angiographic severity of coron ary artery disease, Lp(a) appeared to be remarkably higher in patients with acute ischemic syndromes (unstable angina, myocardial infarction ) than in patients with stable angina. In conclusion, Lp(a) was roughl y twice as high in acute (unstable angina, myocardial infarction) than in chronic (stable angina) ischemic syndromes, but there was no diffe rence between chronic stable angina and non-IHD. Serum level determina tion of Lp(a) made a poor contribution in predicting the extent of cor onary artery disease.